Abstract
Hydrogen assisted subcritical cleavage of the ferrite matrix occurs during fatigue of a duplex stainless steel in gaseous hydrogen. The ferrite fails by a cyclic cleavage mechanism and fatigue crack growth rates are independent of frequency between 0.1 and 5 Hz. Macroscopic crack growth rates are controlled by the fraction of ferrite grains cleaving along the crack front, which can be related to the maximum stress intensity, Kmax. A superposition model is developed to predict simultaneously the effects of stress intensity range (ΔK) and K ratio (Kmin/Kmax). The effect of Kmax is rationalised by a local cleavage criterion which requires a critical tensile stress, normal to the {001} cleavage plane, acting over a critical distance within an embrittled zone at the crack tip. © 1991.
Original language | English |
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Pages (from-to) | 1367-1376 |
Number of pages | 10 |
Journal | Acta Metallurgica et Materialia |
Volume | 39 |
Issue number | 6 |
DOIs | |
Publication status | Published - Jun 1991 |
Keywords
- hydrogen
- iron and steel metallography
- stresses
- Ferrite
- fatigue crack propagation
- stainless steel